Ok so i tried searching and couldn't find anyone who has had this same issue. 3 days ago i noticed the car overheating on the highway. Scared the living crap out of me, and so i pulled over turned the car off and it cooled and was fine. Now every morning and afternoon to and from work, as soon as i get on the highway, the car comes to temp(just under half way mark), then it will go up to 3/4 way no matter how easy i am on the car. Then, it drops back to slightly less than half(normal) after 20-30 seconds. I can then literally beet the crap out of the car and it wont happen again. It usually takes a couple hours for the car to cool completely before i can get this process to repeat. So like i said the car heats up normal, then goes to about 3/4 mark, then drops to normal after about 20 - 30 seconds after being hot. Is there air in the lines>? Any help would be greatly appreciated.

-Ryan

 

Maybe the thermostat is going out..

 

Was just going to say sounds like the thermostat is starting to go. If so its a cheap fix. Thank God for all the blessings no matter how small!

 

sounds good, does anyone know if mitsu usually carries them on hand? I just ran to autozone and they were out! Also, i dont wanna sound like an idiot, btu can you buy coolant premixed at th 50:50 ratio like it says to use in the manual? And if so what kind would anyone suggest? Thanks once agin for the help!

 

they may not have one in stock for u, but mitsu is the best place to get one. 50/50 will be fine in ur radiator..some evo owners adjust the ratio but if u have sub-freezing temp winters, which im sure u do, stick to 50/50. i use prestone coolant in all my vehicles and always works great

 

Prestone sells pre-mixed anti-freeze. I would speculate the thermosthat to be your first culprit. Check your coolant level as well. If you dont have coolant, there is your issue.